Failure in Physics
Dr. John Mather delivers his plenary talk, “The James Webb Space Telescope—Science Opportunities and Mission Progress,” at the 2012 Quadrennial Physics Congress, November 9, 2012.
Failure is the essence of progress, in a particular way; if we never fail, then we just aren’t trying very hard. But “failure” isn’t real, like a proton is. It’s only a label. And it seems a little unnecessary for a physicist to decide that a certain subset of all the possible configurations of the natural universe qualifies for that label.
Abstraction aside, though, the failure of my thesis project on its first flight was pretty darned important to me. The project was conceived by my adviser, Paul Richards, and I worked on it at the University of California, Berkeley, along with two other grad students: David Woody and Norman Nishioka. It was a balloon-borne, far-infrared spectrometer designed to measure the spectrum of the cosmic microwave background radiation (CMBR), and it was quite ingenious.
The CMBR was predicted in 1948 and would become the strongest proof yet that the expanding universe theory is correct. (The name “big bang” implies to most people that there was a time before time, which is linguistically meaningless and not implied by the observations.) But to know that the CMBR is a predicted remnant of the big bang, we needed to confirm that it has the right spectrum and that it comes almost equally from all directions, not from a local source.
The CMBR had been discovered in 1965, but its status as evidence of the early universe was a little uncertain, since a number of faulty measurements had already disagreed dramatically with the predicted 3 kelvin blackbody spectrum. Our payload was to rise above 99 percent of the Earth’s atmosphere to get a look between the atmospheric emission lines using a polarizing Michelson interferometer immersed in liquid helium to suppress thermal emission from the instrument and enable sensitive detections.
After working on the project for what seemed like forever, in the fall of 1973 we decided that it was time to try a launch, which our team had never done before. David and I drove the payload to the balloon base in Palestine, TX. With help from Paul and professional engineers from Berkeley and the balloon base, we prepared it for launch. The launch was successful. The payload went up and up, and then let down 2,000 feet of unrolled cable that should have allowed the payload to observe the sky, not just the balloon overhead.
Imagine our chagrin when the instrument did not work. There was nothing we could do except sit in the control room and watch the data come in. The motor that was to move the interferometer did not turn, and the detector reported an oscillating signal that should not have been there.
As I recall, we were all too tired to display a lot of emotion; the job at hand was now to retrieve the payload and figure out what happened so we could fly again. Paul was very generous and let me write a thesis about the instrument that did not work (and about a ground-based instrument that did work). I hurried off to my upcoming postdoctoral position with Pat Thaddeus at the NASA Goddard Institute for Space Studies in New York City, convinced that this CMBR work was much too hard for a young person.
Dr. Mather answers questions from students following his plenary talk. Photo by Ken Cole.
Meanwhile, David Woody conceived of an inexpensive environmental test chamber (made of plywood and Styrofoam and filled with dry ice) for the payload and quickly discovered what our problems were. The motor didn’t turn because it had rusted on the ground in the moisture of Texas and because its control electronics wouldn’t work cold. The oscillating signal likewise appeared because the detector preamplifier was too cold. David, Paul, and Norm fixed the problems with better electronics and better protection for the motor, flew the payload again, and it worked that time. Later, they upgraded the instrument with liquid helium-3 cooling for the detectors and flew it two more times. The instrument now resides in the Smithsonian National Air and Space Museum in Washington, DC, not far from an overhead model of the Cosmic Background Explorer (COBE) satellite.
What did I learn? Number one, if you do not test something, it will not work. Some people think it’s worth a try anyway, but I think it’s not a matter of chance at all. Nature knows when we are trying to cheat, and Murphy was an optimist. Even if you are tired (or broke), you should not skip the testing.
This came back to me much later when my luck had turned and I was working at NASA’s Goddard Space Flight Center with a huge team of scientists, engineers, and technicians, preparing the COBE for launch. The COBE carried a new and greatly improved version of the balloon-borne instrument, along with two other instruments built to examine the early universe. Over and over I had to resist the temptation to think that I really knew that something was okay to launch.
With a big budget at stake, the temptation to capitulate to management pressure to launch on time was pretty strong. Conversely, after all the expenditure of personal time and public money, we owed it to the taxpayers to get it right and not take chances with their funds. So we tested adequately, and we found some faults and fixed them.
More than three decades after his botched thesis project, John Mather would have cause to smile when he received the Nobel Prize in Physics for his studies of cosmic microwave background radiation. Image credit—NASA.
One was particularly important and was found with a test I might have skipped. The moving calibrator body for the space version of my thesis experiment did not work properly and would have wrecked the mission. I thank my lucky stars every day for (a) my experience of failure with my thesis project and (b) my brilliant colleagues at NASA who knew quite well why we had to test, and didn’t give up. Just about 33 years after that balloon payload failure, I got a call from Stockholm, as did my colleague George Smoot, for our work on the COBE.
Part of the point of this story is that failure is an essential part of research. My friend and noted astrophysicist Harvey Moseley grew up on a farm and describes life there as endlessly fixing broken things. On a farm, you’re pretty much on your own. There is no instruction book and no handy stockroom of spare parts. He says scientific research is much the same, always fixing broken things without an instruction book.
I like to think that we are puzzling out the giant crossword puzzle of the universe, putting in letters and getting them wrong and finding out and fixing them. I imagine the general public thinks our lives are quite different, as brilliant scientists who must know so much. But on the cutting edge of research, we are always looking for things that don’t fit, and the minute we understand something, we go on to the next thing we don’t understand. It takes a certain degree of nerve to do it, considering how little we know. But if you like it, welcome to a thrilling life in science! //
